Nowadays, it's possible to take Roshan at level 1 and get the advantages over the enemy. Imagine when you're start your match with one of your friend already on level 5? Great isn't it? But taking Roshan at level 1 is also risky. If you failed or taking too long, you can start the match under leveled. Here is 7 line up who can kill Roshan even before the creeps appear:
Old School Line Up
+ 2 random heroes
Those 3 is the best combination to kill Roshan. Fury Swipes on Ursa, Frost Amor casted on Syllabear Bear and that's all. But if you pick these hero, i guess most of the team will realize what's your plan ^^ And here's some more combination that's less obvious for Roshan at level 1.
Line Up 1
Skills:
Zeus : Arc Lightning, to get rid of Roshan's linken ability so Panda can use Drunken Haze
Panda : Drunken Haze, make Roshan's attack miss
Enigma : Eidolons, taking from Furion summons
Furion : Force of Nature
Lycan: Howl, adding damage to all the summons and heroes
Items:
Both RoB and Headdress are used for their auras, heroes have random stat items
Level 5 Candidates: Zeus
Line Up 2
Skills:
Broodmother : Incapacitating Bite, slow
Dazzle : Shadow Wave, heal
Shadow Fiend : Presence of the Dark Lord, reduce armor aura
Templar Assassin : Meld, reduce armor
Alchemist : Acid Spray, reduce armor
Items:
Both RoB and Headdress are used for their auras, Stat items for hitter
Level 5 Candidates:Broodmother, Shadow Fiend, Templar Assassin
Line Up 3
Skills:
Ursa Warrior : Fury Swipes for obvious reason, stacking damage
Crystal Maiden : Crystal Nova, slow effect
Omniknight : Purification, heal
Witch Doctor : Voodoo Restoration, heal
Skeleton King : Vampiric Aura
Items:
Both RoB and Headdress are used for their auras, Stat items for hitter
Level 5 Candidates :Ursa Warrior
Line Up 4
Skills:
Juggernaut : Healing Ward, heal
Lich : Frost Armor, slow Roshan when hit the tanker
Tidehunter : Gush, reduce armor
Vengeful Spirit : Wave of Terror, reduce armor
Rhasta : Shackles, remove Roshan's linken for Gush
Items:
Both RoB and Headdress are used for their auras, Stat items for hitter
Level 5 Candidates : Lich, Juggernaut
Line Up 5
Skills:
Beastmaster : Inner Beast, attack speed aura
Drow Ranger : Frost Arrows
Lina : Light Strike Array, stun
Venomancer : Plague Ward
Abaddon : Aphotic Shield
Items:
Both RoB and Headdress are used for their auras, Stat items for hitter
Level 5 Candidates : Beastmaster, Lina
Line Up 6
Skills:
Rooftrellen : Living Armor
Morphling : Morph, max the Agility for max damage
Syllabear : Summon Spirit Bear, tanking damage
Enchantress : Nature's Attendants, heal
Viper : Nethertoxin, add damage
Items:
Both RoB and Headdress are used for their auras, Stat items for hitter
Level 5 Candidates : Viper
This is just for fun, good luck :)
Source : http://www.dota-blog.com/
